scskmsr

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GemSAFE

For Microsoft Internet
Explorer and Microsoft
Outlook Express
User Guide
Version 1.1
21 December 1998
At press time, this document was as thorough and correct as possible, the information
contained herein may however have been updated after this date.
Gemplus reserves the right to change the functions and specifications of its products at
any time without prior notice.
This document was prepared by Gemplus for both its clients and for its own internal
use. The information contained herein is the sole property of Gemplus and shall not
under any circumstances be reproduced without prior consent of the company.
© Copyright Gemplus, 1998.
Smart Cards and Smart Card Readers are patent protected by Innovatronand produced
by Gemplus under license.
Patented by Bull CP8 - Patented by Innovatron.
GemSAFE is a trademark of Gemplus
MS-DOS® and Windows® are registered trademarks of Microsoft Corporation
Internet Explorer and Outlook Express are registered trademarks of Microsoft
Corporation
Netscape and Netscape Navigator are registered trademarks of Netscape
Communications Corporation
Printed in France.
GEMPLUS, B.P. 100, 13881 GEMENOS CEDEX, FRANCE.
Tel: +33 (0)4.42.36.50.00 Fax: +33 (0)4.42.36.50.90
Document Reference: E5213241/DPD08271A00
IMPORTANT NOTICE
Warranty
Gemplus warrants this GemSAFE™ product to be physically free of any defects in
manufacturing and workmanship. No other warranties may be implied nor are
enforceable according to international law and any authority.
Gemplus makes nor representation or warranties, either expressed or implied, by or
with respect to this GemSAFE™ product, and shall not be liable for any implied
warranties of merchantability, of non-infringement of third parties’ rights, of error
free and of fitness for a particular purpose or for any indirect, special or
consequential damages.
Limitation of
Liability
Except to the warranty provisions above, in no event shall Gemplus and its affiliates
be liable for incidental, consequential or special damages, including loss of profit,
loss of data, corrupted or misdirected data, whether based on contract, tort or any
other legal theory. Gemplus bears no responsibility whatsoever with respect to the
use, sale or other disposition of any product incorporating this GemSAFE™ product,
in particular Gemplus makes no warranty as to the physical or logical security and
protection of this GemSAFE™ product.
Copyrights
Any copyright, patent right, trademark, trade secret, mask work and any other
intellectual and/or industrial property right in this GemSAFE™ product, its related
documentation and this publication are and will remain the property of Gemplus. No
part of this publication may be reproduced, stored in a retrieval system or
transmitted in any form or by means electronic, mechanical, photocopying,
recording or otherwise without the prior written consent of Gemplus. No patent
liability is assumed with respect to the uses of any information contained herein.
Trademarks
“GemSAFE” is a trademark of Gemplus.
All written instructions or guidelines contained herein on the use of trademarks,
copyrights or of other ownership rights of Gemplus shall be duly followed. All use
of Gemplus trademarks and logos shall inure to the benefit of Gemplus.
© GEMPLUS
iii
CONTENTS
IMPORTANT NOTICE.................................................................................... III
Warranty ..................................................................................................... iii
Limitation of Liability.................................................................................. iii
Copyrights................................................................................................... iii
Trademarks ................................................................................................. iii
CONTENTS .......................................................................................................IV
OVERVIEW.........................................................................................................1
What is GemSAFE Used For?........................................................................1
Connecting to the GemSAFE Web Site ..........................................................1
The Need for GemSAFE................................................................................2
CRYPTOGRAPHY BASICS AND PUBLIC KEY ALGORITHMS ..................3
Cryptography.................................................................................................3
Encryption.....................................................................................................3
Public-Key Cryptography.......................................................................3
Who does the Key-Pair Belong To? ........................................................3
Digital Envelopes...................................................................................4
Digital Signatures ..........................................................................................4
Digital Certificates.........................................................................................5
The Role of the Certificate Authority .............................................................5
GEMSAFE SECURITY FEATURES..................................................................6
SSL and S/MIME ..........................................................................................6
The SSL Protocol ...................................................................................6
Message Privacy..........................................................................6
Message Integrity ........................................................................6
Mutual Authentication.................................................................6
S/MIME.................................................................................................7
Private Messaging .......................................................................7
Sender Authentication and Tamper Detection ..............................7
Compatibility ..............................................................................7
CERTIFICATE MANAGEMENT ......................................................................8
Obtaining Your Own Certificate ....................................................................8
Who Do You Trust? ......................................................................................8
Authorities .............................................................................................8
Adding a CA........................................................................................ 10
Deleting a Certificate ........................................................................... 10
Identification........................................................................................ 11
ACCESSING SECURE SITES .......................................................................... 13
© GEMPLUS
iv
CONTENTS
Identifying Secure Web Sites ....................................................................... 13
Pre-Filtering......................................................................................... 13
The SSL Handshake .................................................................................... 13
The SSL Process.......................................................................................... 13
SENDING SECURE MESSAGES ..................................................................... 15
Initializing Secure E-mail ............................................................................ 15
Selecting the Certificate............................................................................... 15
Directories ........................................................................................... 15
Reception of a Signed Mail .................................................................. 16
Message Default Setting .............................................................................. 16
Ways to Send Messages............................................................................... 16
Key Length and Secure E-mails ................................................................... 17
LEVELS OF SECURITY .................................................................................. 18
Public Key and Symmetric Key Length........................................................ 18
THE CARD DETAILS TOOL........................................................................... 19
PIN Code Management ........................................................................ 19
Unblocking the PIN Code.......................................................... 20
Changing a Pin Code ................................................................. 20
GLOSSARY ....................................................................................................... 21
© GEMPLUS
v
OVERVIEW
GemSAFE is a smart card-based solution which is primarily designed to secure
electronic mail (e-mail) communication and web sessions on the Internet.
This solution combines the privacy, tamper-detection (integrity) and proof of origin
(authentication) functionality provided by cryptographic algorithms with the
simplicity, portability and convenience of smart cards.
What is
GemSAFE
Used For?
The GemSAFE smart card securely stores your personal secret information and
thus prevents anyone from usurping your identity. Indeed, your password must be
presented before your private keys can be used. The security improvement the
GemSAFE offers as compared to software-only solutions is that your keys are
stored in your smart card and never leave it.
The latest standards such as SSL3 (for web access ) or S/MIME (for e-mail ) enable
inter-operability (that is, compatibility ) of security services between any browser
interface and any web server. For example, although S/MIME is designed to
exchange secure e-mails, you can also use the same mail application to send regular
(unsecured) E-mails.
But the security hole in these protocols is the management of your personal keys and
certificate. Indeed, these can easily be tampered with if you save them on your PC.
Travelling with your electronic identity in pocket, you can securely access on-line
services with your personal smart card, protected by a PIN code, from any machine
in the world. In addition, your card also performs cryptographic algorithms, so that
your private keys never leave the card. Just plug your smart card into any reader
connected to any internet terminal equipped with the GemSAFE software. With
the GemSAFE solution, you no longer are dependet on your own computer.
Connecting to
the GemSAFE
Web Site
© GEMPLUS
Additional information is available on the GemSAFE web site; its address is:
http://www.gemplus.com/GemSAFE
1
OVERVIEW
The Need for
GemSAFE
Figure 1 illustrates in detail the way GemSAFE meets your electronic mail and
internet surfing security needs, as it provides added privacy, tamper-detection and
authentication.
With this solution, nobody can impersonate you, or read encrypted e-mails meant for
you without:
• Having your GemSAFE card, and,
• Knowing your PIN code.
Why Do I Need Security ?
For E-Mail
For Web Surfing
I Want Privacy
I Want Privacy
so that
so that
Built-In Browser Security Features
Only Intended Recipients can read the e-mails
I send.
Nobody can eavesdrop on conversations I have
with servers.
Only I can read the e-mails others send me.
See 1.
I Want Tamper Detection (Integrity)
I Want Tamper Detection
so that
so that
(Integrity)
Any modification of the data en route is detected.
I can be sure the e-mail has not been
modified en route.
I Want Proof of Origin (Authentication)
I Want Proof of Identity (Authentication)
so that
so that
I am sure I know who really sent the mail.
I am sure I know who the server really is.
Others can be sure that e-mails I send really
come from me. See 2.
The server can find out who I am (if it so wishes).
See 3.
Why Do I Need GemSAFE ?
1. To read secure e-mails sent to me, I need my card
and my PIN code.
3. To prove to a www server who I am, I need my card
and PIN code.
2. To prove to others that an e-mail comes from me, I
need my card and PIN code.
Figure 1 - The Purpose of the GemSAFE Solution
The improvement provided by the use of the GemSAFE card (as opposed to
software-only solutions) consists of:
• The fact the keys never leave your smart card
• PIN code protection of key use
• GemSAFE portability: you are no longer restricted to a single PC. You can use
your GemSAFE card from any PC connected to the Net anywhere in the
world, provided the GemSAFE software is installed on it.
© GEMPLUS
2
CRYPTOGRAPHY BASICS AND PUBLIC KEY
ALGORITHMS
Note: If you are familiar with cryptographic concepts and with public-key
cryptographic systems in particular, you may wish to skip this chapter.
Cryptography
In the GemSAFE™ secure e-mail and web context, cryptography consists of
applying mathematical transformations to transmitted data in order to satisfy one or
more of the three following objectives:
1.
Privacy: the transmitted data can not be read by a third party
2.
Tamper detection (also known as integrity): the recipient can be sure that the
data was not modified en route
3.
Proof of origin (also known as authentication): the recipient can be sure who
really sent the data
In public-key systems, privacy is achieved by encryption; tamper detection and
proof of origin are obtained by means of digital signatures.
Encryption
Public-Key
Cryptography
Encryption implies data is scrambled (ciphered) by the sender using an encryption
key, before being sent to the recipient. When it arrives, the recipient uses a
decryption key to unscramble (decipher) the data. Scrambling and unscrambling are
performed using well known mathematical algorithms (with GemSAFE™, the RSA
algorithm is used) and the encryption key simply is a number that feeds into these
algorithms.
In public-key (or asymmetric) cryptographic systems, the decryption and encryption
keys are not the same. The sensitive element is the decryption key, since the person
who has a copy of this key can decrypt the data. Normally, only the recipient has a
copy of this decryption key which must be safely kept (for example stored in the
GemSAFE™ smart card). However, the recipient freely distributes a copy the
encryption key to anybody who is likely to need to send this person something
securely.
The mathematical properties of these keys are such that anything encrypted with the
encryption key (known as the public key because everybody has a copy) can only be
decrypted with the corresponding decryption key (known as the private key because
only the recipient has a copy). This means that anybody can send the recipient
scrambled data, but only the recipient can unscramble it. The public and private keys
together constitute what is known as a key-pair.
Who does the
Key-Pair Belong
To?
© GEMPLUS
How does a sender know that a particular key-pair corresponds to you? You might
have sent the public key by e-mail, or the sender might have retrieved it from a
server, but this would not prevent a spy from changing it en route and substituting
his/her own public key instead. The solution to this problem is digital certification
(see the section entitled Digital Certificates).
3
CRYPTOGRAPHY BASICS AND PUBLIC KEY ALGORITHMS
Digital Envelopes
The mathematical algorithms involved in public key systems are slow. Thus, if there
are multiple recipients (for example, if you send all your colleagues an encrypted email) or if the data is large (several megabytes, for instance), the encryption of
several megabytes will probably require several minutes and will have to be
repeated for each recipient (since each has a different public-key). A solution known
as digital envelopes is used to resolve this problem. Because symmetric or secretkey algorithms (where the decryption and encryption keys are the same, examples
include RC2, RC4, DES and DES3) are much quicker, the following steps are
carried out:
The sender:
1.
Generates a random symmetric key (which is only a few bytes long)
2.
Encrypts the bulk data with the random symmetric key (fast)
3.
For each recipient, encrypts the random symmetric key with the recipient’s
public key
4.
Transmits the output of steps 2 and 3 to all the recipients
The recipients:
1. Decrypt the random symmetric key using their private key,
2. Use their random symmetric key to decrypt the bulk data (fast).
As a result, the bulk of the data is encrypted only once with a very fast algorithm.
Digital
Signatures
A digital signature provides proof of origin and tamper detection. It consists of
sending additional information (known as a signature) along with the original data
which proves to the recipient that the received data is word for word identical to the
data the sender intended to send.
Digital signing of data is completely independent from data encryption. Data can be
both signed and encrypted, signed only, encrypted only and, of course, neither
signed nor encrypted.
Since each person involved already has a private key (which is kept secret by its
owner) and a corresponding public key (which everybody knows) for encryption
purposes, a good system might consist of re-using these keys. The signature is
calculated by the sender and sent along with the data to the recipient. Its value is a
mathematical function of the sender's private key and the data to be sent. The
construction of the algorithm is such that it is not possible to calculate this value
without knowing the private key.
The recipient can verify that the data received corresponds to the data that was
signed by the sender using another mathematical algorithm which relies upon the
sender's public key, the signature, and the data received.
© GEMPLUS
4
CRYPTOGRAPHY BASICS AND PUBLIC KEY ALGORITHMS
Digital
Certificates
When the same key-pair is used for encryption and signature, this key-pair
corresponds to a sort of on-line identity. You can use it to sign data (e-mails,
expense claims, random challenges sent by web servers, etc.) and decrypt data that is
meant only for you (incoming e-mails, etc.). The GemSAFE™ solution means that
this identity (the private key) is securely stored in a smart card and it never comes
out. Any calculations that are performed using this key are done by the card itself.
The system relies on the fact everybody knows that a particular key-pair is linked to
you. This is the purpose of digital certificates. A key pair without a corresponding
digital certificate is effectively useless.
The Role of the
Certificate
Authority
By issuing a certificate, the Certification Authority (CA) basically states that "Public
key 1234… corresponds to a private key that only Mr. Smith or Company XYZ has
access to ". Anybody who trusts the CA can, for example, encrypt an e-mail for Mr.
Smith’s eyes only, or verify a digital signature created by Company XYZ.
This binding of a real-world identity (Mr. Smith in this example) to a digital identity
(Mr. Smith’s key pair) is performed using a digital signature. The CA has its own
key-pair which is used to sign the concatenation of Mr Smith's public key and the
name "Mr. Smith" (along with a host of other useful things such as the certificate’s
validity date, etc.).
Certification Authorities usually charge a fee for this binding task. Indeed,
depending on the company’s policy, the CA may pay a visit to the person it is
vouching for to verify it actually is who it claims to be, or it may need a letter from
this person’s employer certifying he/she works there, etc. The CA may also offer
other value-added services, such a public directory of the certificates that it has
issued.
To determine whether you should trust a particular CA, you first need to look at the
CA’s policy statement to check that it performs a type of check that you find
appropriate before issuing its certificate (what guarantees does the CA provide?
what is the legal position?)
Secondly, you need to recover a copy of the CA’s public key so you can verify the
CA’s digital signatures. It is convenient to recover this public key within a
certificate (since the certificate also provides validity dates and other relevant
elements).
This certificate may be signed by the CA itself or by yet another CA whom you
already trust. In the former case, the certificate cannot be independently verified and
its integrity must be validated by other means (for example, using the certificate’s
independently transmitted 'fingerprint').
© GEMPLUS
5
GEMSAFE SECURITY FEATURES
SSL and S/MIME
The GemSAFE solution complements two key security standards:
• The SSL/TLS (Secure Socket Layer/Transport Layer Security) is a protocol
between the server and the browser, which operates over the Internet.
• The S/MIME (Secure Multipart Internet Mail Encoding) is a message format
designed to secure e-mail messages.
Note:
The SSL Protocol
TLS is the latest standardized version by the Internet Engineering Task
Force (IETF) of SSL.
SSL is an on-line protocol which may provide privacy over the internet as it allows
client/server applications to communicate in a way that cannot be eavesdropped.
SSL offers the following basic features: message privacy, message integrity and
mutual authentication.
Message Privacy
Message privacy can be achieved through encryption. All traffic between an SSL
server and an SSL client is encrypted using a key and an encryption algorithm
negotiated during the SSL handshake (see The SSL Handshake).
Message Integrity
The message integrity service ensures that SSL session traffic is not modified on the
way to its final destination. SSL uses the combination of a shared secret and special
mathematical functions (called hash functions) to provide the message integrity
service.
Mutual
Authentication
Mutual authentication is the process whereby the server convinces the client of its
identity and the user convinces the server of its identity. These identities are coded
in the form of public-key certificates (X509), and these certificates are exchanged
during the SSL handshake.
To demonstrate that the entity presenting the certificate is the legitimate certificate
owner (i.e., has access to the private key which corresponds to the public key in the
certificate) rather than an impostor, the other entity may require that the certificate
presenter digitally sign data exchanged during the handshake (see Digital
Signatures).
The entities sign protocol data to prove they are the legitimate owner of the
certificate. This prevents someone from masquerading as you by presenting your
certificate. The certificate itself does not authenticate; the combination of both the
certificate and the proof that you have access to the corresponding private key does,
however (see Digital Certificates).
Note:
© GEMPLUS
Server authentication is always required by the browser with the SSL
protocol, whereas client authentication may or may not be systematically
required by the server.
6
GEMSAFE SECURITY FEATURES
S/MIME
S/MIME is an off-line message format standard implemented for use with the
Microsoft Outlook Express mail application, which is designed to encrypt and
digitally sign electronic mail.
S/MIME offers users the following basic features:
•
•
•
•
Encryption for message privacy
Sender authentication with digital signatures
Tamper detection
Compatibility with any other S/MIME-compliant software
Private
Messaging
S/MIME's encryption helps ensure that your messages remain private. Microsoft
Outlook Express software supports domestic and export-level public key and
symmetric key encryption.
Sender
Authentication
and Tamper
Detection
S/MIME authenticates the message sender by reading the sender's digital signature
(the recipient can see who signed the message and view the certificate for additional
detail ).
Compatibility
Because S/MIME is an open standard, the mail software client can operate with
other S/MIME-compliant clients (for example, if you are operating with Microsoft
Outlook Express, you can correspond with someone equipped with Netscape
Messenger (which is S/MIME-compliant)).
© GEMPLUS
7
CERTIFICATE MANAGEMENT
If you do not already have a preferred Certificate Authority (CA) who will issue
your certificate, you can find a list of CAs on the GemSAFE site
(http://www.gemplus.com/GemSAFE). Some of these CAs offer free certificates
for testing and demonstration purposes.
Obtaining Your
Own Certificate
1. Contact a CA.
2. Fill out the required information. This data varies with each CA, but it usually
includes at least your name and e-mail address.
Figure 2- Getting a Certificate
Once you have received your certificate, you can view it by clicking View, Internet
Options, Content, Certificates and Personal. All your certificates are then
displayed. Bear in mind you can only store one certificate in your card at a time. All
other certificates are located in the software.
If you need to change the certificate in your card, see Deleting a Certificate.
If your GemSAFE™ card contains a certificate that was not installed using IE4 on
your PC, you need to initialize the PC for this certificate using the GemSAFE™
Card Details tool. (See The Card Details Tool).
Who Do You
Trust?
Authorities
When you first try to access a secure web site or receive a secure e-mail, you may
receive a message stating that the CA which signed the server’s certificate (or
another user’s certificate) is unknown. This simply means that your browser does
not have a certificate for this CA and that you need to add it to your list if you want
to proceed with a secure web session or verify a user’s certificate.
Note:
© GEMPLUS
Your browser already has a number of Certificate Authorities it accepts
by default. To view this list of CAs click View, Internet Options,Content,
Certificates , then click Authorities.
8
CERTIFICATE MANAGEMENT
Figure 3- The Internet Options Content Screen
Figure 4- List of Trusted Certificate Authorities
© GEMPLUS
9
CERTIFICATE MANAGEMENT
Adding a CA
The process of adding a CA to your browser’s list consists of getting the CA’s
certificate over the Internet (using a directory, for instance) and verifying its
integrity by checking that its fingerprint (a digest of the certificate) matches the
fingerprint sent to you by independent means.
In practice, from the CA’s web site, download the CA’s certificate. The New CA’s
certificate is displayed (see Figure 5).
Figure 5 - Adding a New CA’s Certificate
If you click OK, the message “Do you want to ADD the following certificate to the
Root Store?” is displayed. Click Yes.
You thus confirm the installation of the new CA’s certificate.
Deleting a
Certificate
A GemSAFE card is only designed to store one certificate at a time. If you have a
certificate on your card and wish to obtain a new one, the old certificate will
automatically be deleted.
To view your current certificate, click:
•
•
•
•
View
Internet Options
Content
Personal
Figure 6 shows the Properties screen which is displayed at this point.
© GEMPLUS
10
CERTIFICATE MANAGEMENT
Figure 6 - Viewing Your Certificates
Identification
To verify that the CA’s certificate is valid, you need the CA’s public key beforehand
(it is located in the CA’s certificate). It may be obtained in various ways (including
an e-mail from the CA, the CA’s web site, a directory...).
CA ABC
Server 1
Server 2
Server 3
Private key
CA ABC's job is to provide a signed certificate ensuring that it has verified that Server 1 is who it
claims to be.
Server 1's Certificate
Includes the Server's Name,
Public Key and the certificate's validity date
CA ABC's
Signature
Figure 7 - The Server, the CA and the Signed Certificate
To send someone a secure mail, you need to add this person’s certificate to your
address book, and in order to do this, you must first receive a signed mail from your
intended recipient or look up this recipient’s certificate in a directory.
To view your address book from within Microsoft Outlook Express, click:
• Tools
• Address Book
© GEMPLUS
11
CERTIFICATE MANAGEMENT
Figure 8 shows the Address Book screen which is displayed at this point.
Figure 8 - The Address Book
If you double click a name in the address book list, the properties related to this
address book entry are displayed (see Figure 9).
Figure 9 - Address Book Properties
© GEMPLUS
12
ACCESSING SECURE SITES
The GemSAFE™ web site contains a list of secure servers that can be used for
testing purposes.
To access the GemSAFE site, type the following location from your Microsoft
browser:
http://www.gemplus.com/GemSAFE
Identifying
Secure Web
Sites
Pre-Filtering
The SSL
Handshake
Secure sessions rely on the SSL protocol. All secure web sites are accessed using the
https:// prefix (that is, the address must start with this prefix if you want to
communicate with a secure site).
If your browser has a certificate on file for the CA corresponding to the secure site
you wish to access (and if your browser has a certificate to present to confirm who
you are, in the event client authentication is requested by the server), then you may
proceed with your secure session.
If your card has a certificate that is not accepted by the server, it will not be
displayed in the list box showing the certificates that can be used with the server. In
this case, you cannot connect to the server.
The SSL handshake takes place each time you start a secure web session. This
operation identifies the server and it is automatically performed by your browser.
Note:
The SSL handshake can only succeed if the server’s certificate is still
valid.
Figure 10 - Sample SSL Page
The SSL
Process
© GEMPLUS
If you want to have a secure web session with Server 1, you may want to make
certain that Server 1 is indeed who it claims to be (the real Server 1 and not another
entity impersonating it). In this case, you will want a certificate ensuring this from
Server 1’s CA. Of course, you also will have to make sure that the certificate you
receive comes from the genuine CA and not from some entity impersonating it!
13
ACCESSING SECURE SITES
1. You start the SSL operation by sending the server a random number. The server
returns a certificate and a signature of the random number. The certificate
provides the server’s public key, and the signature proves that the server
currently has the private key corresponding to the certificate it is sending.
Client Random
Server
Client
Certificate +
Signature of
Random
Figure 11 - The SSL Process
2. Now the CA’s signature needs to be verified. This is done by comparing the
CA’s public key obtained in the certificate received in the previous step to the
public key in a certificate obtained by other means (usually from a directory or a
public list).
3. Your browser now checks that the name in the certificate matches the name you
typed (e.g., test.gemsafe.com).
© GEMPLUS
14
SENDING SECURE MESSAGES
Initializing
Secure E-mail
To initialize your secure e-mail, you need to link your certificate to your mail
account. To do so, open Microsoft Outlook Express and click:
• Tools
• Accounts
• Select the Mail tab
• Select the mail account to be used from the list displayed
Click:
• Properties
• Security
and verify that the box next to “Use a digital id when sending secure messages from
XYZ address” is checked.
If this is greyed, check that the E-mail address in your certificate corresponds to that
configured for Microsoft Outlook Express.
Selecting the
Certificate
Before you are ready to send someone an encrypted message, you need a current
certificate for this person.
To this effect, you need to receive a signed mail from this person, or you need to
look up this person’s certificate (from a directory, for example), to compare it with
the signed certificate you received.
Note:
Directories
When you want to send an encrypted mail to a list of persons, you need a
certificate for each addressee, or your mail will not go out to anyone.
To locate a user in a directory, click:
• Edit
• Find People
Figure 12 - Finding Someone Using a Directory
© GEMPLUS
15
SENDING SECURE MESSAGES
Reception of a
Signed Mail
People’s certificates are not stored automatically by your browser. Thus, you need to
add the user and the user’s certificate to your address book. To do so, when you are
in the incoming message signed by that person, click:
• Tools
• Add to Address Book
Message Default
Setting
To change the default setting, click:
• Tools
• Options
• Security
• Secure Mail
At this point, you may opt to digitally sign all messages or to encrypt the contents
and attachments for all outgoing messages, thus turning the security on by default.
To view the list of people you know (that is, for which you may or may not have a
certificate), click:
• Tools
• Address Book
Select the person by double-clicking the name.
Now click Digital Ids to view the certificates associated with the user.
Your browser also automatically checks that the name in the e-mail address you are
writing to corresponds to the name in the certificate.
Similarly, when you receive a message, your browser checks that the e-mail address
of the sender matches the sender’s certificate.
Ways to Send
Messages
1. My message is “Hello”. I send it in plain-text.
2. My message is “Hello”. I encrypt it using the recipient’s certificate (which
includes the recipient’s public key). I have obtained this certificate either from a
public source of information, such as a directory, or from a previous mail the
recipient sent me in the past. The message becomes “gobbledigook”. The
recipient deciphers it using his/her private key.
This provides confidentiality and privacy.
3. My message is “Hello”. I send it in plain-text with my signature and my digital
certificate (which includes my public key). The certificate may be used by the
recipient to verify my signature.
This provides authenticity and integrity.
4. My message is “Hello”. I concatenate this message with my signature and my
certificate and encipher the result.
This is equal to 3. plus 2. and it therefore provides privacy, authenticity and
integrity.
© GEMPLUS
16
SENDING SECURE MESSAGES
Key Length and
Secure E-mails
There are various levels of security depending on the length of the keys used. This
length is primarily dictated by the laws of the country you are in. If you are located
in the USA, for instance, you may be able to generate keys of a length of 168 bits.
However, in the international version of Netscape the maximum authorized key
length is 40 bits. Thus, a message sent from the USA using a 168-bit key cannot be
deciphered in France, for example (where browsers do not have a 168-bit option for
the key length).
Therefore, bear in mind what the addressee’s cryptographic capacity is before
sending the message, or it may be impossible for this person to read your message!
Your preferred algorithm can be viewed by clicking:
• Tools
• Options
• Security
• Advanced Settings
For additional information about key lengths, see Levels of Security.
© GEMPLUS
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LEVELS OF SECURITY
There are different versions of the Microsoft browsers. The length of the keys your
browser uses depends on U.S. export rules and on applicable regulations in your
country.
Public Key and
Symmetric Key
Length
Outside of the United States, the length of the RSA public/private key pair (which is
used for signing, verifying, etc.) is often limited to 512 bits, while the symmetric key
(used for bulk encryption) usually is 40 bits long.
Therefore, depending on the country you are located in, you may find you have
many or few options to choose from, to set the key length.
Note:
© GEMPLUS
The symmetric key length is determined by both the browser and the card.
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THE CARD DETAILS TOOL
Under Windows95 and WindowsNT 4.0, if you have not recovered a certificate
using Microsoft IE on the same PC you plan to use SSL/SMIME with, then you
need to initialize the PC the first time you use your smart card with this certificate.
Click:
• The Windows Start Menu
• Programs
• GemSAFE Card Details
Follow the instructions as they appear on the screen.
The GemSAFE Card Details Tool also provides a status of the certificate and keys in
the card, and PIN code management.
Figure 13 - Certificate Registration
PIN Code
Management
Your GemSAFE card is protected by a PIN code. This PIN code must be four to
eight digits long.
Three wrong PIN code presentations lock the card and therefore prevent its further
use. To access the PIN code management section from the GemSAFE Card Details,
click:
• PIN
• Verify User PIN
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19
THE CARD DETAILS TOOL
Unblocking the
PIN Code
Figure 14 - Unblocking the PIN Code
If your PIN code is blocked, click:
• PIN
• Unblock
Follow the instructions as they appear on the screen.
Changing a Pin
Code
To change either your user or your adminstration (unblocking) PIN code, click:
• PIN
• Change
Select either your user PIN code or your administrative PIN code. Enter your old
password and the new one as per instructions on the screen.
Figure 15 - Changing the PIN Code
Your PIN code must not exceed a length of eight digits.
Note:
© GEMPLUS
The default is 1 2 3 4 for both the user and the administrative PIN codes.
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GLOSSARY
© GEMPLUS
Certificate
A certificate provides identification for secure
transactions. It consists of a public key and other
data, all of which has been digitally signed by a
Certificate Authority (CA). It is a condition for
access to secure e-mail or to secure web sites.
Fingerprint
A digest of a certificate.
SSL
(Secure Socket Layer/Transport Layer Security)
Communicating protocol used between servers
and browsers for secure web sessions.
SSL Handshake
The SSL handshake (which takes place each time
you start a secure web session) identifies the
server. It is automatically performed by your
browser.
S/MIME
Off-line message format standard for use in
secure mail applications.
www
World Wide Web
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